The present invention concerns novel phenolic derivatives of thiadiazole compounds and their use as multifunctional additives for lubricating compositions. More particularly, the novel thiadiazoles are derived from 2,5-dimercapto-1,3,4-thiadiazole, an aldehyde and a phenolic compound.
Additives known as antiwear agents are employed to increase the load-carrying capacity of lubricants. The antiwear additives promote the formation of a surface film and thereby prevent wear of the contacting metal surfaces.
During the course of use, lubricants are susceptible to deterioration due to oxidation. The oxidative process leads to the loss of lubricating properties and inadequate protection of the device to be lubricated. Antioxidants are added to inhibit the oxidative process. Therefore, it is desirable that antiwear agents possess antioxidant properties.
U.S. Pat. No. 2,850,453 discloses symmetrical phenolic derivatives of 1,3,4-thiadiazole which possess corrosion and oxidation inhibiting properties when incorporated into lubricating oils. However, due to stricter environmental controls, there is a need for new and more effective ashless-type additives, preferably possessing multifunctional properties.